(19)
(11) EP 0 483 082 A3

(12) EUROPEAN PATENT APPLICATION

(88) Date of publication A3:
19.11.1992 Bulletin 1992/47

(43) Date of publication A2:
29.04.1992 Bulletin 1992/18

(21) Application number: 91830436.1

(22) Date of filing: 15.10.1991
(51) International Patent Classification (IPC)5: H05B 41/38, H05B 41/392, H05B 41/29
(84) Designated Contracting States:
DE ES FR GB NL SE

(30) Priority: 22.10.1990 IT 6781290

(71) Applicant: MAGNETI MARELLI S.p.A.
I-20145 Milano (IT)

(72) Inventors:
  • Nepote, Andrea
    I-10147 Torino (IT)
  • Boella, Marcello
    I-10015 Ivrea (Torino) (IT)

(74) Representative: Quinterno, Giuseppe et al
c/o JACOBACCI & PERANI S.p.A. Corso Regio Parco, 27
10152 Torino
10152 Torino (IT)


(56) References cited: : 
   
       


    (54) Device for controlling a gas-discharge lamp for use in a motor vehicle


    (57) The device includes a circuit (15) for generating signals indicative of a reference current which is variable in steps and, during successive time intervals defined by a clock-signal generator (41), decreases according to respective predetermined functions as the voltage detected across the lamp (L) increases, these functions corresponding substantially to respective predefined constant values of the power supplied to the lamp (L), and a differential comparator circuit (10) which compares the values of the reference current generated with the current detected in the lamp (L) and generates an error signal in dependence on the difference between them. The error signal can be used to control the device (1) for supplying the lamp (L).






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